Disk Storage in AWS

• Disks have a scope of AZ, i.e. a disk can be attached to EC2 instance running in Same Avaliability Zone.
• Disks in AWS are majorly categorized as root disk (with OS) and secondary disks (add on disks)
• While creating an EC2 instance in the Add Storage tab the following view appears
• Disks can be added to the EC2 instance while creating or post creation
• Delete on Termination, Root disk is by default selected for delete on termination which can be changed.

Possiblities in EC2 disk

• Whenever we create an ec2 instance, which is launched on some physical server in AWS AZ, the possibility of disk is
  • Disk can be created in same physical server and mounted to EC2
  • Disk can be create in different physical Server and mounted to EC2
• Disks which are created in Same Physical Server on which ec2 is launched
  • Access of the data will be very fast
  • Whenever ec2 instance is deleted the disk will be deleted
  • They are called as ephemeral storage
• Disk which is created in Different Physical Server than ec2
  • Access of the data will be slow compared to above
  • Whenenver ec2 instance is delted the disk will still exist
  • Non-ephemeral storage
• In AWS all the root disks have to be Non Ephemeral

Instance Store

• Is the Ephemeral Storage option of AWS.
• It is supported only on few instance types
• For instance storage supported instance types, the value of instance storage will have number of disks and the size in it. BUt the root volume is still EBS

• Storage size is fixed

Elastic Block Storage (EBS)

• Is the Non Ephemeral and default storage option for root volumes
• It is supported by all aws instance types
• In the EC2 machine where the instance storage option is EBS only, only EBS volumes are allowed to be attached
• EBS has flexibile sizing options, (Elastic Volumes)
  • you can start with a disk of size 1 GiB
  • Increase the size to 2 GiB while your instance is running
• EBS volumes backups are called as snapshots.

Exercise: Create an Ec2 instance with one root disk and one ebs volume (1GiB)

• Created an ec2 instance with one root volume (8 GiB) and one ebs volume (1GiB)
• All the volumes belong to same AZ
• Resizing root volumes and additional volumes can be done (Resizing needs to dealt diffrentely which we will be discussing in our subsequent classes)
• EC2 Billing:
  • EC2 instance :
    • Billing will be stopped when you stop ec2 instance
  • Volume:
    • Billing will be stopped when you delete volume